基于安全系统学原理的爆炸物品管理

爆炸物品管理是一个繁杂而艰巨的系统工程,运用安全系统学原理研究和指导爆炸物品管理工作是十分契合的,又是十分必要和重要的。在构建爆炸物品管理的安全系统结构模型,确定爆炸物品管理安全系统综合指标体系及其权重的基础上,提出了爆炸物品管理系统安全、科学、高效运行的措施。     

Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) — Preliminary study on TATP and PETN

The application of isotopic techniques to investigations requiring the provision of evidence to a Court is limited. The objective of this research was to investigate the application of light stable isotopes and isotope ratio mass spectrometry (IRMS) to solve complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques.Due to the current threat of organic peroxide explosives, such as triacetone triperoxide (TATP), research was undertaken to determine the potential of IRMS to differentiate samples of TATP that had been manufactured utilising different starting materials and/or manufacturing processes. In addition, due to the prevalence of pentaerythritoltetranitrate (PETN) in detonators, detonating cord, and boosters, the potential of the IRMS technique to differentiate PETN samples from different sources was also investigated.Carbon isotope values were measured in fourteen TATP samples, with three definite groups appearing in the initial sample set based on the carbon data alone. Four additional TATP samples (in a second set of samples) were distinguishable utilising the carbon and hydrogen isotopic compositions individually, and also in combination with the oxygen isotope values. The 3D plot of the carbon, oxygen and hydrogen data demonstrated the clear discrimination of the four samples of TATP. The carbon and nitrogen isotope values measured from fifteen PETN samples, allowed samples from different sources to be readily discriminated.This paper demonstrates the successful application of IRMS to the analysis of explosives of forensic interest to assist in discriminating samples from different sources. This research represents a preliminary evaluation of the IRMS technique for the measurement of stable isotope values in TATP and PETN samples, and supports the dedication of resources for a full evaluation of this application in order to achieve Court reportable IRMS results.     

Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS) — Discrimination of ammonium nitrate sources

An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures.The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid.Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed.The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material.     

The impact of force,time, and rotation on the transfer of ammonium nitrate: A reductionist approach to understanding evidence dynamics

Empirical studies evaluating the conditions under which the transfer of forensic materials occurs can provide contextual information and offer insight into how that material may have been transferred in a given scenario. Here, a reductionist approach was taken to assess the impact of force, time, and rotation on the transfer of an explosive compound. An Instron ElectroPuls E3000 material testing instrument was used to bring porous and non-porous surfaces adulterated with an ammonium nitrate into direct contact with a human skin analogue, controlling for the force of contact, duration of contact, and rotation applied during contact. Quantifiable amounts of ammonium nitrate were recovered from all of the recipient surfaces demonstrating that ammonium nitrate is readily transferred from one surface to another, even when contact occurs for a short duration with a relatively low force. More particulates were transferred from non-porous surfaces onto the human skin analogue, but the amount of ammonium nitrate transferred did not depend upon the force of contact, duration of contact, or the amount of rotation applied. However, when contact occurred and involved rotation, a greater transfer of ammonium nitrate was observed, compared to those contacts occurring without rotation being applied. This approach complements more commonly-used holistic experiments that test multiple interacting variables in a realistic setting by isolating these variables, allowing them to be examined individually. This can be utilised to better understand the individual impact that specific variables have on the transfer of trace evidence in relevant crime reconstruction contexts.     

对我国民用爆炸物品安全管理的若干思考

民爆物品管理涉及多个部门,民爆物品管理中的问题在各个部门的管理环节都可能存在不足。民用爆炸物品管理是一项复杂的系统工程,要确保民用爆炸物品管理的有效性,应采取整合企业、完善国家民用爆炸物品信息管理系统、建立健全危险物品现场监管机制、多管齐下打击涉爆犯罪等多种措施。     

Rapid changes in profiles from stored materials used in scent training of explosive detection dogs

Canines trained on scents from materials emitting vapours of explosives and related compounds are widely used to detect explosives in civilian, military and forensic applications. Despite the importance of these training materials, there is limited knowledge on how long these subsamples can be stored and whether vapour profiles change over time. We developed a sampling methodology that makes use of a secondary chamber for stabilisation of headspace concentration to allow reliable and reproducible determination of scent profiles. The effect of aging was investigated by following the response of volatile markers emitted from eight common explosives in open and closed containers over two months or two years. The initial headspace air volume consisted of a wide variety of chemical substances related to explosives, with levels varying in magnitude from low ppb to ppm. All included subsamples were affected by aging by demonstrating exponentially lower levels, and five subsamples showed a significant change in their scent profile. The dominant components decreased on a short time scale for plastic explosives based on RDX, PETN and dynamite as well as for granules of octol and ammonium nitrate mixed with fuel. For flakes of TNT, granules of Comp B and nitrocellulose powder, headspace air concentrations declined, but the overall character of their profiles were in general more stable. The overall changes, i.e., lower levels and/or changed profiles, justifies regular checks of the scent status of training materials. Considering these results together with data displaying marginal changes in energetic performance, it is advisable to complement scent training with training materials subjected to different durations of aging.